A 27-year-old woman was admitted to hospital with a 5-months history of difficulty in swallowing, hoarseness and increasing headaches since the last gestation trimester of her second pregnancy. Concerning her previous history, she reported that the same symptoms had occurred during the first gestation and had fully resolved after delivery. On neurological examination, a facial paresis and deafness were present on the right side. The patient also presented a significant dysfunction of the right IX, X and XI cranial nerves.

RADIOLOGICAL FINDINGS:

Axial CT in bone window showed the destruction of the mastoid portion of the petrous bone by the lower parts of the tumor (Fig. 1A). The upper parts of the tumor revealed massive calcifications with compression of the brainstem (Fig 1B). MRI demonstrated a lobulated temporal bone mass with invasion of the right jugular foramen. T2-weighted, axial MRI of the mastoid part of the tumor exhibited an intermediate signal indicating solid tumor (Fig. 1C) and at the level of the brainstem-compressing part of the tumor showed hypointense signal corresponding to calcification (Fig. 1D). T2-weighted, coronal MRI revealed the extent of the tumor and the significant brainstem-compression. The inferior non-calcified and the superior calcified parts of the tumor could be well differentiated (Fig. 1E). Coronal, postcontrast T1-weighted MRI demonstrated enhancement of the non-calcified parts of the tumor (Fig. 1F). Preoperative angiography and tumor embolisation were indicated. The selective angiography revealed a moderate, capillary tumor blush fed by the ascending pharyngeal and the external occipital arteries.

An embolisation with calibrated polyvinyl-alcohol-particles was preoperatively performed. Intraoperatively, the tumor was adherent to the cranial nerves and was removed by a postauricular transtemporal approach. The calcified portion compressing the brain stem was resected with a diamond drill. In the immediate postoperative course, the patient experienced an accentuation of the lower cranial nerves dysfunction with progressive improvement on follow-up.

GROSS AND MICROSCOPIC PATHOLOGY:

Macroscopically, the tumor revealed a brown and dark red color and was of firm consistency with varying calcified portions. Microscopic examination disclosed two well-demarcated components within the tumor (Fig. 2A). Predominating were highly cellular areas consisting of ovoid to spindled cells and numerous osteoclast-like multinucleated giant cells that frequently contained cytoplasmic vacuoles (Fig. 2B). In these areas few typical mitoses occurred (Fig. 2C). Aside, minor lobulated areas consisted of round or polygonal-shaped cells with ovoid, grooved, hyperchromatic nuclei, surrounded by an eosinophilic chondroid matrix (Fig. 2D). Here, most cells lacked well-defined cellular margins and occasionally showed perinuclear empty spaces (Fig. 2E). Calcifications were predominantly found in the minor lobulated areas of the tumor and displayed a patchy or geographic pattern (Fig. 2A). Intercellular calcifications, so called chicken-wire-like calcifications, were not observed. Very rarely small foci of necrosis without signs of calcification were found, most likely due to prior tumor embolization (Fig. 2E, bottom right side). No marked nuclear atypia was seen. Within the tumor and at the tumor margins occasionally some siderophages appeared (Fig. 2F).